Is it permissible to combine goats and sheep if neither of them completes the Nisab on their own?

A: A person should calculate the number of ewes with the number of rams to complete the Nisab, and Zakah (obligatory charity) is to be paid from any of them according to their own value. In this regard, Al-Muwaffaq, in his book entitled Al-Mughny, and others say: "There is no dispute among scholars over joining various kinds of species together in Zakah." So, it is permissible to give Zakah from any of the two kinds on the basis of their own value.